This answer is on the NI site at
http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/862567530=
005f09c862564e17e89?OpenDocument
It sounds like the serial port you are trying to configure is in use
already.=A0 Make sure no other application is trying to access that
port.
Sorry about that answer. I missed the part about searching in
developer exchange. I don't know how to specialize searches in
developer exchange.
This sounds like a good approach. I think I will give it a try in my
next update.
Thanks for your response, Ryan. The only problem with that approach
is that I am getting data every two seconds and I would like the data
to go with the date of the file, i.e. I could potentially get about 10
seconds worth of data in the previous day's file. Not a big deal, but
I already have suc
How would you recommend that I schedule a file-creation process to
occur at midnight each day during a long term data logging operation
in LV6.1?
I am operating a continuous system that logs data over a period of
years. There are large amounts of data being logged and I have a
technique for namin
Glad to help. I have been there too often. It's amazing how much
time is spent making simple problems complicated. Hopefully, some of
the other discussion items will be of benefit in future tasks.
-jayme
I work on an Apple machine, so the answer is no, but I will see if I
can find a Windows machine with 6.1.
Determine wheter or not you have a straight through serial cable or a
null modem cable. If it is null modem, your device will probably not
properly receive the commands because it will be "listening" to the
wrong wires in the cable.
If you sent the string out_sp_00, then the data stream was 10
bytes long, one byte per ASCII character, of which the character
is the last. This corresponds to 80 bits. At a baud rate of 4800,
this should take 80/4800 = 17 ms. Since your timeout value was set to
something larger than 1 second,
Maybe that, or the data byte configuration is wrong. The 7 data bits
seems a bit unusual. I have communicated with about 15 different
devices over the course of my LabVIEW programming and 8 data bits is
the only configuration that I have encountered. The stop bit is
probably 1.0.
Hung, double c
= carriage return = 0x0A hex
= linefeed= 0x0D hex
It is rare to get a timeout when writing. I usually get this when I
am reading a port. What value did you use for the timeout when you
configured the port? I think the default is 10,000 ms, i.e. 10
seconds. If it were timing out, you would notice the code hanging for
10 seconds as the serial I/
Please, be more specific. Do you want to count crossings that may be
due to noise, or do you want to discriminate against the noise and
count zero crossings from a band-limited signal?
Pardon me, but your sentence structure was hard to decipher. I think
you are asking a very basic question. If you want to know how to
simply create the array, you have many options. All are found in the
array tools sub-pallette.
You can use the "initialize array.vi". First, put a numeric const
Ah, yes, serial communication is supposed to be simple, but it is
often frustrating. I have done a fair amount of this, but none under
LV7.
Whether or not you get errors depends on the nature of the
communication. For instance, suppose you send a request for status
information to your serial dev
The low level register access functions are called "read" and "write".
They have changed names over the years and I think they are platform
dependent.
The low level register access functions are called "read" and "write".
They have changed names over the years and I think they are platform
dependent.
You can pass structures to dlls, but you may have to write a wrapper
function to get the format right. If the c-code structure does not
match a LV data type, you have to cast it, so-to-speak, in your
wrapper function. The ability to write such a wrapper function is a
good skill to have. Read som
As I suspected. Besides some introductory level knowledge of Pascal
and C, I do not have the benefit of programming experience in other
languages, nor time spent on Info-LabVIEW. I find that it is fairly
easy to get the job done in LabVIEW without a more general
understanding of the text-based pr
LabVIEWer's suggestion is better because you should be able to move
the pop-up graph to see both charts at the same time. To do that with
my example, you have to make extra space in the main vi to put the
charts side by side.
I want to thank you guys, Greg and Rolf, for taking the time to
elaborate on the issue and encourage you to do so in the future. You
both seem very knowledgeable and it helps to get a better
understanding of what is really going on with the code. I have been
operating under some flawed assumption
Thanks for your insight, Greg. I was surprised to learn that global
references each contain a copy of the data. This implies that each
time data is written to a global, each copy of that global must get
updated. The process sounds amazingly inefficient. Now I know why
globals are taboo in LabV
Sounds like you are passing a 100MB array to your sub-vi. As soon as
you do this, you make a copy of the data. That is, the input variable
is not a reference to the array, it is a copy of the array. To
understand this more clearly, think about wiring the same array to
four or five different sub-
Oops, I committed a bad programming sin. I forgot to close my control
reference to the string. If you do that, the code should be
acceptable.
-jayme
The only ways I know to do what you want to do is 1)to create your own
graphs using a picture control and the drawing functions (It is a lot
of work.) or 2)to create your own offsets in an overlayed chart, turn
off the scale and build your own scale with a picture control (also a
lot of work).
You
I found that even when I choose "fit to contents" the tab control does
not automatically resize. They "autogrow" just fine, but they don't
"autoshrink". I had to programmatically adjust the tab size to get it
to work right.
There is always room for improvement for the LV development team.
They get a lot of their ideas for improvement from these discussions.
Hopefully, this "font scaling" issue will be addressed in a future
version of LV.
I'm glad you found my answer helpful. Thanks for the good rating.;-)
jayme
Your buttons scale fine until you reach the limits of the text box.
When you try to shrink the panel below the limit of the Boolean text
box size, you find that the button shrinks no further. Then when you
expand again, the panel forgets that the shrink operation was limited,
and all of the button
If the APIs are well documented, it is a breeze. You need the
function prototype which is found in header files and in the function
definitions in good API documentation. The prototype contains the
name of the function and the calling syntax, including the type
specifications for the input parame
What display control are you usng to display your image? That is, on
which control is the scrollbar causing problems? Is it a color image?
I have done live image aquisition without Vision in the past. I have
displayed the image using a picture control and using an intensity
graph control. Sound
I can help you get started with your project, but first, please,
provide more information. Do you have to keep your database in MS
Notepad files, or can you create datalog files in LabvIEW to serve as
your databases. Things are much easier for you if you can work
directly with LabvIEW data struct
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